Which boxers were masters at the craft of putting their man away early...? Dempsey, Tyson, McClellan? Those are some of the obvious choices. Who else?
Terry McGovern was arguably the pioneer of the genra not to mention one of the better all time examples.
Ricardo "Pajarito" Moreno certainly deserves a mention here, he had loads of early KO`s in his career. For those of you who don`t know who Moreno was, try picturing Bob Satterfield as a featherweight. Ricardo was a terrific puncher with both fists who either knocked you out or got knocked out, as he had a less than reliable set of whiskers and usually went all out from the first bell which would see him run out of gas after a few rounds. He was also notorious for his lax training habits and voracious appetite for women and booze, a real wild man that Moreno was. I only have his bouts versus Hogan Bassey (LKO3) and Davey Moore (LKO1), but from the Bassey fight it is clear that Moreno was a devastating hitter as he had Hogan on ***** street from one slight clip on the jaw in the first round of their bout. I wish there was more film of him out there, from what some other folks I know who saw him fight live told me he was right up there with KO Bob when it came to delivering excitement and drama to a fight. We sure could use guys like Moreno and Satterfield around today, they would be TV legends on ESPN FNF and eventually on HBO, and would give the fans their money`s worth every time out.
While I don't really disagree with the heart of the question... the quality of opposition always needs to be considered. I.E. just 'cause Dempsey KOed a lot of tomato cans early on doesn't out of necessity make him a great KO artist.